LCL filter resonance mitigation technique for voltage source converters

This paper investigates the control technique to mitigate the LCL filter resonance issue for voltage source converters. Two level voltage source converter with and without passive damping of LCL filter are selected for the comparative study. Control algorithm is discussed to estimate the source impedance based on variable carrier PWM. Estimated source impedance is used to tune the control of the VSC to avoid the resonance of LCL filter has been presented. There have been scenarios when LCL resonance can´t be avoided just by tuning the control parameter. In these cases energy efficient technique has been discussed which allows running voltage source converter with minimum performance difference. Simulation studies have been performed to evaluate the above techniques and verified with the experimental results.